Mark Webber set the fastest time in the final practice session ahead of qualifying for the Singapore Grand Prix after inching out Jenson Button for the top spot.
Webber's best time of 1:46.081 was the fastest of the weekend so far but just 0.027s quicker than Button in the McLaren, who put together a smooth and controlled lap between the barriers of the Marina Bay circuit. Friday's pacesetter Sebastian Vettel was third fastest after a frustrating end to the session that saw his best lap ruined by a slower car in the final sector and his subsequent efforts similarly blocked. He finished 0.264s off the pace but will almost certainly find more time when it matters in qualifying.
Fernando Alonso took his Ferrari to the ragged edge to eke out the fourth fastest time of the session, 0.315s off Webber. He was the first driver to set a time on the supersoft tyres and held onto the top spot briefly before the Red Bulls and Button joined him on the faster compound.
Lewis Hamilton was fifth fastest but did post a completely manage a clean lap and at one stage sustained damage to his diffuser as he rode the kerb on the exit of turn seven. His best effort was 0.855s off Webber, but again there is undoubtedly more time for him to find ahead of Q3 this evening.
A gap of nearly a second divided Hamilton and Nico Rosberg back in sixth, who was just 0.006 faster than Mercedes team-mate Michael Schumacher in seventh. Both were quicker than Felipe Massa who struggled to hook up a decent lap and was 2.630s off Webber's benchmark.
Kamui Kobayahsi and Adrian Sutil rounded out the top ten as their respective teams Sauber and Force India look to sneak some points out of this weekend. Toro Rosso and Williams are not too far behind and will be entertaining thoughts of top ten spot in qualifying as the Renaults continued to struggle back in 16th and 17th.
At the very back of the field the HRTs and Virgins strayed around the 107% mark that could see them fail to qualify, but both teams should be okay when it comes to Q1 this evening.